Advertising has traditionally been distributed in printed publications, and typically placed to exploit the editorial context, the locality of the publication's distribution, and the demographic of its readership.
In more recent times advertising has been distributed as part of Web pages. The Web page advertising space is typically specifically allocated for, and dedicated to, advertising. Advertisements typically are often customised and targeted based on the page being viewed or the search being carried out by the user. If the user is registered with the site the advertising may be targeted to the user's demographic based on the user's known profile.